import java.util.*;

 
public class Hello 
{
  final int N = 10;
  
	public static void main(String[] args) 
	{  
		int arr[] = new int [5];
		int n = arr.length ;
		
		
		System.out.printf("\nArray length = %d" , n);

        Scanner sc = new Scanner(System.in); 
        
        System.out.println("\nEnter Number : ");
        
		int num = sc.nextInt();
		int i;
		int factorial = i = 1 ;
		
		while(i <= num)
		{
			factorial *=  i ;
			i++;
		}
		
		 System.out.println("factorial n=" + num + " :  " + factorial);
      
	}

}

 